Automatic rewind switch



July 14, 1931. w. G. PREDDEY 1,314,739

AUTOMATIC REWIND SWITCH Filed Aug. 27, 1928 INVENTOR. MLTEI? 611 950055 n-rm l llpp I Patented July 14, 1931 UNITED STATES PATENT QFFICE AUTOMATIC BEWIND SWITCH Application filed August 27, 1828.

loaded reel from which the film is to be removed, and the empty reel which is to receive the film. The end of the film is attached to the empty reel, and then this reel is rotated by a motor or other source of power for winding the film thereupon. If any break should occur 1n the film or 1f the film has been completely wound upon the formerly empty reel, some means must be provided for bringin the reel to a stop, otherwise the free end of the film on the rotating reel will thrash around and will likely become damaged.

The principal object of the present inven tion is to provide means for automat cally cutting off the current to the motor driving the winding reel when the film breaks or when the end of the film has been reached. The current to the motor is cut off by the opening of an automatic switch, and this switch is designed to be automatically opened when the tension upon the feeding reel is released. It should be noted that the film in unwinding from the loaded reel creates a certain amount of pull or tor ue upon the axis of the shaft supporting this reel, and I utilize this force for controlling the switch.

A further object of my invention is to provide a device of the type described which is positively locked in open position and re mains so until the switch is again manually closed. he device is extremely simple in construction and is durable and efiicient for the purpose intended.

Other objects and advantages will appear as the specification proceeds, and the novel features will be particularly pointed out in the appended claims.

My invention is illustrated in the accom- Serial No. 302,250.

panying drawings forming a part of this application, in which Figure 1 shows a rear View of a rewind cabinet for moving picture films;

Figure 2 shows a rear elevation of the switch and associated mechanism, the cover to the switch being broken away for clarity;

Figure 3 is a view similar to Figure 2 but showing the parts in operative position;

Figure l is a section along the line l 1 of Figure 2; and

Figure 5 is a detail section of a part of the device.

In carrying out my invention, I make use of a rewind cabinet indicated generally at 1. This cabinet has compartments 2 for reels of films, and carries two shafts 3 and al. An empty reel 5 is mounted upon the shaft 3, while a full reel 6 (see Figure 4) is mounted upon the shaft l. Figure 1 shows how the film 7 is fed from the full reel 6 to the empty one 5.

The shaft 3 carries a large pulley 8, and this is connected to the pulley 9 of a motor 10 by means of a belt 11. Any other suit able drive may be used for connecting the shaft 3 with the motor 10 without departing from the spirit and scope of my invention.

I will now describe the switch and its associate mechanism. The switch is housed in a casing 12, and is covered by a plate 13. The casing encloses a portion of the shaft 4: (see Figure 4). The casing is secured to the cabinet 1 by screws ll or other suitable fastening means, which are inserted through arms 15. The inner wall 16 of the casing supports a bearing 17, while the cover 13 carries a second bearing 18 (see Figure d). The shaft 4 is rotatively mounted in these hearings and has an enlarged portion 19 bearing against the wall 16, which prevents the shaft from moving to the right. A look collar 20 is mounted upon the shaft l and prevents movement of this shaft to the left.

The shaft d is reduced as at 21, and this reduced portion receives the reel 6. A key 22 causes the reel and shaft to rotate as a unit. The reel is locked in place by a spring-pressed arm 23, this arm being shown in detail in Figure 5 A spring-pressed cuit to the motor 10.

plunger 24-. looks the arm 23 in the position shown in Figure or in the position shown rod 29 when raised closes the contacts 27 and 28. The rod 29 and the arm 25 are heavy enough to swing into open position. The rod may be manually held in raised position for keeping the switch closed. I provide automatic means for keeping the switch closed, this means being actuated by the rotating shaft i.

In higue i l show a weight 80 as being loosely mounted upon the shaft This weight is in the shape shown in Figure 2, and it tends to swing into the full-line position shown in this figure when the shaft t either ceases to rotate or materially reduces its speed of rotation. A web 31 of the weight is slightly spaced from one face of the collar 20. A fiber washer 32 or other friction device is placed between the flange and the collar. A second collar is adjustably secured to the shaft 4;, and provides a stop for a spring 34. The other end of the spring bears against a disc 35, movable onv the shaft 4., this disc bearing against a fiber asher 86' and causing the latter to frictionally engage the flange 81. The ends of the spring enter the disc 35 and the collar 33, which causes the disc 35 to rotate with the collar 32-).

From the foregoing description of the various parts of the device, the operation thereof may be readily unde stood.

The full reel is placed upon the shaft 4. and the empty reel is placed upon the shaft The film 7 is connected to the reel 5, and then the rod 29 is raised for closing the cir- The motor rotates the reel 5, and the winding of the film 7 upon this reel rotates the shaft 4. The disc 85 and spring 34 frictionally engage with the weight 30 and tend to rotate this weight with the shaft 4. If the shaft 4 should happen to be rotating in a counter-clockwise direction when looking at Figure 3, the weight 30 will swing into the position shown in this figure. The weight is eccentrically mounted upon the shaft 4, and when it is swung into the position shown, it will contact with the bottom of an adjustable member 37 and will hold this member in raised position. The member is secured to the arm 25, and therefore the arm is held in raised position and keeps the switch closed.

Should a break occur in the film or should the end of the film be reached, the shaft -l would cease rotating and the weight 80 would instantly fall into the position shown in Figure 2, which would permit the switch to open and cut off the circuit to the motor so that the reel 5 would also be brought to a stop. The adjustable member 37 drops into a recess 38. This recess has shoulders 39 which engages with the side of the ad justable member 37 and prevent the raising of this member and the switch arm should the weight 80 for some reason be swung on the shaft 4-. t is necessary for the operator to again raise the rod 29 before the switch can be closed.

It should be further be noted that the device will function whether the shaft rotates in one direction or not. The self-locking feature eliminates any accident occurring to the operator should the shaft 4 be suddenly rotated. The counterweight insures a positive locking and stopping in the event of a break on a partially rewound heavy reel. It should further be noted that the weight 30 creates a certain tension upon the shaft l, and this insures a tight rewinding of the film upon the reel 5. The double bearings 17 and 18 offer a greater support to the shaft and prevent a wobbling of the shaft, which gives a more positive operation to the device. One movement of the control handle or rod 29 is all that is necessary to start the device functioning, regardless in which direction the reel 6 is rotate -l.

Although I have shown and described one embodiment of my invention, it is to be understood that the same is susceptible of various changes, and I reserve the right to employ such changes as may come within the scope of the invention as claimed.

I claim:

1. An automatic rewind switch having contacts normally held in open position, a revolving shaft, manual means for closing said contacts, automatic means for keeping said contacts closed when said shaft revolves at a predetermined speed, said automatic means including means for keeping said contacts from closing unless said manual means is again actuated.

2. An automatic switch asosciated with a rotatable shaft, and comprising two terminals normally disposed in open position, manually controlled means independent of said shaft for closing said terminals, and means operated by the rotating shaft for holding said switch closed after it has once been manually closed.

3. A switch having one of its contacts swinga-ble into open position by gravity, a rotatable shaft, a member eccentrically mounted 011 said shaft, yielding means connecting said member to said shaft for causing said shaft to swing said member when the shaft is rotated, a second member depending from the movable contact and riding on the first member, said members holding said contacts together when said shaft rotates, said first named member having a recess therein for receiving said second named member when said shaft drops below a predetermined speed, said recess having walls for preventing said first named member from lifting the second named member when the shaft is again rotated.

4. An automatic rewind switch comprising a pair of contacts, a shaft rotatable in either direction, manually-controlled means for moving said contacts together, means movable by the rotating shaft for holding said contacts together, said means including a member for freeing said contacts when said shaft comes to a stop or decreases its speed, and means engageable with said member for preventing the member from swinging the contacts into closed position when the member has once freed the contacts until said manually-controlled means is again operated.

5. A switch comprising a fixed contact, a second contact movable into open position by gravity, a rotatable shaft, a disc rotatably mounted on said shaft and having a recess therein, yielding means connecting said disc to said shaft for causing said shaft to swing said disc when the shaft is rotated, an adjustable member carried by the movable contact and riding on the periphery of the disc when lifted and when the disc is swung into operative position, said member being receivable in the recess whenthe shaft drops to a predetermined speed, said recess having walls for preventing said disc from lifting said member when the shaft is again rotated.

6. An automatic rewind switch comprising a shaft rotatable in either direction, a weight loosely mounted upon said shaft, friction means connecting said weight with said shaft for causing a movement of the weight when the shaft is rotated, a movable switch arm, manuallycontrolled means for raising said arm, said arm dropping into inoperative position by gravity, said weight holding said arm in operative position as long as the shaft is rotated, and a stop carried by said arm and engaging with said weight for preventing the latter from moving the former into operative position until the arm is again manually lifted when once the arm, has dropped.

7. An automatic rewind switch comprising a pair of contacts, a shaft rotatable in either direction, manually-controlled means for moving said contacts together, means movable by the shaft when the same is rotated in either direction for closing said contacts, said means including a member for freeing said contacts when said shaft comes to a stop or decreases its speed, and means engageable with said member for preventing the member from swinging the contacts into closed position when the member has once freed the contacts until said manually-controlled means is again actuated.

8. An automatic rewind switch having contacts normally held in open position, a shaft rotatable in either direction, manual means for closing said contacts, automatic means for keeping said contacts closed when said shaft revolves at a predetermined speed in either direction, said automatic means including means for keeping said contacts from closing unless said manual means is again actuated.

9. An automatic switch associated with a shaft rotatable in either direction, and comprising two terminals normally disposed in open position, manually controlled means independent of said shaft for closing said terminals, and means operated when theshaft is rotated in either direction for holding said switch closed after it has been manually closed.

10. An automatic rewind switch comprising a shaft, a weight frictionally secured to the shaft and being movable therewith when the shaft is rotated, a movable switch arm, manually-controlled means for raising said arm, said arm dropping into inoperative position by gravity, said weight holding said arm in operatire position as long as the shaft is rotated, and cooperative parts carried by the arm and weight for preventing the latterfrom moving the former into operative position until the arm is again manually lifted when once the arm has dropped.

WVALTER G. PREDDEY. 

